DISSECTION OF THE UPPER LIMB. 



and first rib 

 relations ; 

 use. 



AXILLARY 

 ARTERY I 



extent ; 



depth. 



above small 

 pectoral ; 



with 



muscles, 



and nerves. 



Beneath 

 pectoral 



with 

 muscles, 



vein, 



and nerves. 



And beyond 

 the small 

 pectoral : 

 with 

 muscles, 



with vein, 

 and nerves. 



between the two rough impressions for the costo- and coraco- 

 clavicular ligaments. 



The muscle crosses the large vessels and nerves of the liml>, and 

 is enclosed, as before said, in a sheath of fascia. 



Action. It depresses the clavicle, and indirectly the scapula. 



The AXILLARY ARTERY (figs. 6 and 7) continues the subclavian 

 trunk to the upper limb. The part of the vessel to which this name 

 is applied is contained in the axilla, and extends from the 

 outer border of the first rib to the lower edge of the teres 

 major muscle (H). 



In the axillary space its position will be marked by a line from 

 the centre of the clavicle to the inner edge of the coraco-brachialis. 

 Its direction will vary with the position of the limb to the trunk ; 

 for when the arm lies by the side of the body the vessel is arched, 

 its convexity being upwards ; but when the limb is raised to the 

 level of the shoulder, it is somewhat curved in the opposite direc- 

 tion. In the upper part of the axilla the vessel is deeply placed, 

 but it becomes superficial as it approaches the arm. 



Its relations with the surrounding objects are numerous ; and the 

 description of these will be methodised by dividing the artery into 

 three parts, the first above, the second beneath, and the third below 

 the small pectoral muscle. 



Above the small pectoral muscle, the artery is contained in the 

 axillary sheath of membrane (E), and is concealed by the clavicular 

 portion of the great pectoral muscle. Behind it are the intercostal 

 muscles of the first space and the first digitation of the serratus 

 magnus. 



To the thoracic side is placed the axillary vein (#). The cephalic 

 vein (e) and offsets of the acromio-thoracic vessels cross over it. 



On the acromial side lie the cords of the brachial plexus ; super- 

 ficial to it is the external anterior thoracic nerve ; and beneath it is 

 the posterior or long thoracic, descending on the serratus magnus. 



In its second part, the pectoralis minor and major (B and A) are 

 superficial to the artery. But there is not any muscle immediately 

 in contact behind, for the vessel is placed across the top of the 

 axilla, particularly when the limb is in the position required by the 

 dissection. 



The companion vein (g) lies to the inner side, but separated from 

 the arterial trunk by the inner cord of the brachial plexus, which 

 has crossed behind the artery to its inner side. 



In this position the cords of the brachial plexus lie around it, 

 one being outside, another inside, and the third behind the artery. 



Beyond the pectoralis minor, the artery is at first concealed by 

 the lower border of the great pectoral muscle (A) ; but thence to its 

 termination it is covered only by the integuments and the fascia. 

 Beneath it are subscapularis muscle (F) and the tendons of the 

 latissimus and teres (G and H). To the outer side is the coraco- 

 brachialis muscle (j). 



The axillary vein remains on the thoracic side of the artery. 



In this, its third part, the artery lies in the midst of the large 



